Temperature compensating mounting for basic oxygen furnace



Nov. 29, 1966 c, BUESING ET AL 3,238,453

TEMPERATURE COMPENSATING MOUNTING FOR BASIC OXYGEN FURNACE Filed NOV.12, 1963 FEW/M United States Patent TEMPERATURE COMPENSATING MOUNTINGFOR BASIC OXYGEN FURNACE Arthur C. Buesing and Bela Vitez,'Milwaukee,Wis., as-

siguors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Nov. 12, 1963, Ser. No. 322,817

1 Claim. (Cl. 26636) This invention pertains to a basic oxygen furnaceand more particularly to a means for connecting the furnace to laterallyextending trunnions which permit tilting the furnace to remove thecontents contained therein.

Basic oxygen furnaces or vessels are utilized to produce steel and rangein size from vessels of 150 to 300 tons capacity. Vessels are designedfor 360 degrees rotation. Initially, the vessel must be turnedapproximately 55 degrees from the vertical toward the charging platformto receive the scrap and liquid metal charge prior to blowing. Duringthe blow, the vessel is in a vertical position. Following the blowingoperation, it must be tilted in the opposite direction toward thepouring ladle to transfer or pour off the molten steel. Following theoperation, the transfer ladle is removed and the furnace is tilted to anupside down position, to pour off the slag. It is then returned to theinitial 55 degrees position and the charging cycle is resumed.

It is common practice to provide a trunnion ring about the vessel. Thisring is provided with laterally extending trunnions which are rotatablycontained by the vessel support. The trunnion ring quite frequently isdesigned to provide an air gap between the outer surface of the vesseland the inner surface of the trunnion ring. This air gap permitsexpansion of the vessel during the steel making process. It also reducesheat transfer from the vessel to the ring and hence to the trunnionsupport. However, by providing this air gap between the outer surface ofthe vessel and the inner surface of the trunnion ring, if the vesseldoes not expand evenly into engagement with the ring, the vessel issubject to excessive rocking during the tilting operation. This rockingcould result in damage to the ring as well as dangerous splashing of themolten metal. To overcome this rocking, various fixed stops are providedbetween the trunnion ring and the oxygen vessel. These stops in someinstances may take the shape of a fixed wedge stop or a vertical wedgemay be driven between the trunnion ring and the vessel. None of thepreviously known stops have exhibited the ability to adjust to unequalpressures due to unequal expansion of the vessel. Unequal expansionresults in highly concentrated stresses of such magnitude as to causecracks in the vessel shell or in some instances rupture of the trunnionring.

It is applicants intention and a general object of the subject inventionto provide a basic oxygen furnace which utilizes a trunnion ring havinga stop which insures that the furnace will be maintained and heldagainst excessive rocking while the furnace is being tilted.

A more specific object of the subject invention is to provide a basicoxygen furnace utilizing a trunnion ring with resilient stops betweenthe furnace and the ring to compensate for unequal expansion of thefurnace relative to the ring.

A further object of the subject invention is to provide a basic oxygenfurnace of the hereinbefore described type with a resilient connectionbetween the furnace and the trunnion ring which permits a predeterminedamount of expansion of the furnace before a fixed stop is contacted.

These and other objects of the subject invention will become more fullyapparent as the following description is read in light of the attacheddrawing, wherein:

FliGv 1 is a partial plan view of a basic oxygen vessel incorporatingthe inventive concept of the invention;

FIG. 2 is a partial side elevation cross section taken along the linesII-II of FIG. 1; and

FIG. 3 is a partial section taken along the lines III-III of FIG. 2.

Referring to the drawing, the basic oxygen furnace or vessel generallydesignated 6 has an outer shell 7 and an inner wall 8 constructed of anywell known heat resistant material. As particularly shown in FIG. 1, thebasic oxygen vessel herein disclosed for purposes of illustration iscircular in cross section. It should be understood that any convenientcross sectional shape may be utilized.

In view of the circular cross sectional configuration of the vesseldisclosed for purposes of illustration, an annular trunnion ringgenerally designated 9 is utilized. The trunnion ring may be constructedin any conventional manner and is herein shown as having a rectangularcross section best shown in FIG. 2. Opposite ends of the trunnion ring 9are provided with connection flanges 11 which receive bolts 12 and nuts13 to connect the ring ends. A pair of diametrically opposed supportwheels 10 are rigidly connected to the trunnion ring 9. These wheels aresupported in rollers (not shown) to permit tilting of the vessel. Thegear 15 may be utilized to control the tilting.

As best shown in FIG. 2, the inside diameter of the trunnion ring 9 islarger than the outside diameter of the vessel 6 so that a space 14 isprovided therebetween when the elements are cold. This space is topermit expansion of the vessel relative to the ring as the vesseltemperature increases. To this end it is necessary to provide aconnection between the ring and the vessel which will permit thisrelative radial expansion of the vessel relative to the ring.

As herein shown for purposes of illustration, this connection may beeffected by providing an annular flange 16 about the outer periphery ofthe vessel. This flange 16 provides a sliding annular surface 17 and maybe strengthened by a plurality of ribs 18 and 19 connected to the vesselin any conventional manner such as by welding. An additional flange 21spaced from the flange 16 a distance equal to the height of the trunnionring 9 is also provided about the vessel 6. As herein shown for purposesof illustration, this flange 21 may be C-shaped in cross section and maybe connected to the vessel in any conventional manner, however, isherein shown as being releasably connected by means of bolts 22 and nuts23. Furthermore, to provide a true sliding seat for the trunnion ring 9an additional ring 24 may be provided. With such an arrangement, thetrunnion ring 9 is held about the vessel 6 and between the flanges 16and 21 in a manner which will permit relative radial movement betweenthe vessel and the ring.

As the temperature of the vessel 6 increases, it will expand radiallyoutwardly to decrease the space 14 between the outside of the vessel andthe trunnion ring 9. Because of the extremely high temperature that isattained by the vessel, the space 14 may be as much as four inches.Within this amount of clearance, if the vessel should expand unevenly,which in most cases would be the case, it would not be concentricallylocated or held within the ring 9. If this should be the case, it isquite likely that as the vessel is tilted about the roller 10, it mayrock within the ring which could result in an uncontrolled spilling of aportion of the liquid metal within the vessel. It is, therefore,necessary that the vessel be held within the ring so that it is notpermitted to rock during the tilting operation.

To this end, applicants have provided a plurality of resilient retainers26 to limit the amount of free expansion of the vessel 6 relative to thering 9. As herein shown for purposes of illustration, each retainer isrigidly connected to the trunnion ring 9 in any conventional manner,such as by welding. In the cold position, as shown in the drawings, aspace 27 is provided between the vessel flanges 16 and 21 and theinnermost surface 28 of the retainers 26. This space 27 is less than thespace 14 so that the resiliency of the retainers 26 will in all cases beutilized when the vessel has obtained the minimum workable temperature.As the vessel expands, the flanges 16 and 21 contact the surfaces 28 ofthe retainers 26 and exert a pressure thereon. The resilientcharacteristic of the retainers 26 is such that they will give under theexpanding pressure of the vessel; however, they will exert sufiicientholding force on the vessel so as to hold the vessel against rockingwhen it is tilted.

It should also be noted that the retainers or resilient members areconstructed in such a manner that a positive stop is provided. This maybe accomplished in any conventional manner and is herein shown as beingaccom plished by providing a raised portion or boss 29 directly behindthe surface 28. This raised portion is spaced a distance 31 from theouter end of the surface 28 so that the resilient characteristics willbe experienced until the boss 31 is contacted. Furthermore, the boss 31will be contacted before the furnace shell 7 contacts the ring 9.

It can thus be seen that even though unequal expansion of the vesselshould occur, due to the resiliency of the retainers 26, the vessel willbe held so that rocking will not result. It is possible that one side ofthe vessel will expand so much more than the other side that one or moreof the retainers may be ruptured. However, because the ring is spacedfurther from the furnace, it will not be damaged if some of theretainers do rupture. Furthermore, because of the resiliency of the goodretainers on the opposite side of the furnace, the ring will be shiftedinto engagement with the furnace in the area of the damaged retainers sothat the furnace will be adequately held.

From the above description, it can be seen that applicants havedeveloped a means for supporting a basic oxygen vessel which overcomesthe problem of rocking inherent in previously known basic oxygen furnacesupporting structures. With this arrangement, unequal expansion of thevessel is accommodated by the resilient characteristics of theretainers.

Although only one embodiment of the subject invention has been hereinshown and disclosed, other modifications will be apparent to thoseskilled in the art after this description has been read, and it isintended that all such modifications as come within a reasonableinterpretation of the appended claim be covered.

The embodiments of the invention in which an exelusive property orprivilege is claimed are defined as follows:

A support for a basic oxygen furnace comprising: a pair of flangesrigidly connected to the outer surface of said furnace providing spacedfacing laterally directed annular surfaces; an annular trunnion ringpositioned about said furnace in sliding engagement with said spacedsurfaces, said trunnion ring having an inside diameter larger than theoutside diameter of said furnace; resilient means mounted between saidtrunnion ring and said furnace and adapted to resiliently resist slidingmovement be tween said ring and said furnace only after a predeterminedamount of unresisted movement of said furnace; and stop means mountedbetween said trunnion ring and said furnace and adapted to prohibitrelative movement between said trunnion ring and said furnace after apredetermined amount of movement of said resilient means.

References Cited by the Examiner UNITED STATES PATENTS 3,000,621 9/1961Puxkandl 266-39 3,163,696 12/1964 Johansson et a1. 266-36 3,191,9216/1965 Johnson 266-36 CHARLIE T. MOON, Primary Examiner.

WHITMORE A. WILTZ, Examiner.

J. M. ROMANCHIK, Assistant Examiner.

